class Container {
    static of (value) {
        return new Container(value);
    }
    constructor(value) {
        this._value = value
    }
    map(fn) {
        return Container.of(fn(this._value));
    }
}

class Maybe {
    static of (x) {
        return new Maybe(x);
    }
    isNothing() {
        return this._value === null || this._value == undefined
    }
    constructor(x) {
        this._value = x;
    }
    map(fn) {
        return this.isNothing() ? this: Maybe.of(fn(this._value))
    }
}

module.exports = {Maybe, Container};